Space Camera 3 – Live

With this launch, we have made a image livestream, sending the largest, highest, fastest images ever sent in realtime from the stratosphere by amateurs, with 10mW of radio power – as much as a single LED. We had two payloads attached to a weather balloon, and reached 36km altitude. We sent out and received live images as it was flying, plus GPS information, that everyone could receive and automatically post online for everyone to see – in real time!
All scripts, PCB designs, etc, are all available for you under a creative commons licence. I’ll be posting those later.

Feel free to leave a comment below, providing some feedback, e.g. stating what we can do better next launch, what sensors you would like to see in them, etc!

Flight Statistics

Cost

€150 (just helium+balloon)

Launch

12:36 (11-09-2011 Delft Netherlands)

Touchdown

15:00 (11-09-2011 Heereveen Friesland)

Burst

14:26

Recovery

15:55

Flight Time

2h24m

Max. Altitude

35.748 m (#28 arhab record)

Total Weight

~1300g

Main Payload

Beagleboard/GPS/GPRS/Webcam/Radio

Backup Payload

Arduino/GPS/GPRS/Cutdown

Cutdown

Yes, Hot-Wire

# Pictures Taken

1731 Pictures

# Pictures Sent Live

123 Pictures

# Pictures Received Live

119 Pictures

# Data Received Live

6.000.000 bits

# Max Data Rate

1.200 bits/s

Largest image sent live

800×592 px (#1 record)

3D Distance Traveled

205 km

Minimum inside temp

+5°C

Radio Power

10mW (434.653MHz, 8n2)

Video

An overview (after launch)

Route

The route (no altitude data after burst)

Some Live images we received

We received 5.632.000 bits correctly for our images. These were 119 images that were sent over that we all received almost all entirely. Here is my pic of three images that sum it up.

The first image sent over right before launch

Image sent over live at around 33km altitude. The top part was lost in reception - click on it for full size

Image shot at 36km altitude. When we received this, we knew it had burst above the Ijsselmeer!

3D Stereo roundshot of the Payloads

Retrieving the Payload

Eric had to drive 1 minute to the landing site.

Eric spotted it: hanging from a building!

Payload retrieved!

What was in the Main Payload?

The main payload and its crib

Insides of the main payload

What was in the Backup Payload?

The backup payload

The insides of the backup payload

So how do we send and receive stuff live?

You will learn by watching this video:

1700 images taken, 123 images sent

Sending an image took between 10seconds and 60 seconds. Within the time of sending an image, the webcam had taken much more. So, which one should it send next? The latest? No. Logically it would be, the prettiest or the best. So i made a simple algorithm that chooses the best image from two factors: (1) a mean grey value (2) a 8-bit standard deviation of ideally 30, so, not too much deviation in the image, but also not too little. You can read all about that algorithm in my post here.

Some Other Data

You can clearly see a steady velocity in height. The temperature data is from the backup-payload inside the plastic container. This confirms my theory that you dont need to worry about isolation for temperature, as there is little mass to transfer the cold at -50C at 30km altitude.

14 Responses

Hey I know this is off topic but I was wondering if you knew of any widgets
I could add to my blog that automatically tweet my newest twitter updates.

I’ve been looking for a plug-in like this for quite some time and was hoping maybe you would have some experience with something like this.
Please let me know if you run into anything. I truly enjoy reading your blog and
I look forward to your new updates.

Hey !
I’m following your activities through RSS feed.
Nice post about the flight beginning of september !!
Could you point me where you posted the pictures ?
Thanks !! (looking forward to further posts already !)
Christophe (from France)